1. Field of the Invention
The present invention relates to a photolithography process for carrying out a cleaving in manufacturing a semiconductor laser and more particularly, to a photolithography process for carrying out a cleaving in order to form a reflecting face of a mirror of a laser.
2. Description of the Related Art
Several types of photolithography processes are well known in the art. One of such processes discloses a substrate as shown in FIGS. 1(a) and 1(b).
That is, as shown in FIGS. 1(a) and 1(b), a line 1 is formed on a growth layer 2 disposed on the front face of the substrate by the use of a scribing machine after the substrate has undergone a step of forming a metal electrode and then, it is formed into the shape of a bar as shown in FIG. 1(b). The bar formed in such a way is used in protecting a mirror face 3 of a laser diode by carrying out a coating on the mirror in order to prevent the oxidation of the mirror face.
The cleaving is carried out in such a manner that the diode is cleaved by means of a diamond blade in a state with the growth layer 2 laid upwardly and the cleavings are made at the intervals of 350-300 .mu.m for thereby forming cleaved bars. However, in such a cleaving method, the surface of the growth layer 2 and the edges thereof are damaged to a severe degree so that the mirror face 3 which is closely related with the life expectancy of the laser diode is rendered to be difficult from being protected, which thereby lowers the yield of the chips.